A.5.19 A.5 · Organisational Controls

A.5.19 — Information security in supplier relationships

Define and implement controls to manage information security risks associated with using products or services from suppliers.

Also written as A5.19, Annex A 5.19, ISO 27001:2022 A.5.19, ISO27001 A.5.19.

What ISO 27001 A.5.19 requires

Information security in supplier relationships is one of 37 Organisational Controls in ISO/IEC 27001:2022 Annex A. Define and implement controls to manage information security risks associated with using products or services from suppliers. Organisational controls are judged on governance rather than tooling: an auditor wants a named owner, an approval trail, and evidence the control is exercised on a defined cadence rather than written once and filed.

Audit evidence assessors look for

When preparing your Statement of Applicability (SoA) for A.5.19, gather artefacts such as:

  • Supplier security policy
  • Supplier risk assessment records
  • Security questionnaire / due diligence process documentation
  • Third-party risk register

How A.5.19 maps to SOC 2 and NIST CSF

If you run more than one framework, the same evidence usually satisfies all of them. A.5.19 aligns with:

SOC 2: CC9.2 Vendor and business partner risk

NIST CSF 2.0: GV.SC-01 Supply chain risk management program, GV.SC-04 Suppliers prioritized by criticality, GV.SC-06 Due diligence before supplier relationships

ISO 27001:2013 mapping

A.5.19 consolidates the following ISO 27001:2013 control(s): A.15.1.1. If you are transitioning an existing ISMS, map your prior evidence for these to A.5.19 in your updated SoA.

Map A.5.19 to NIST CSF & SOC 2 →
Crosswalk this control in the Control Mapper & Gap Assessment.
Document the risk →
Record treatment for gaps against A.5.19 in the Risk Register.

Related Annex A controls

A.5.21 Managing information security in the ICT supply chain A.5.23 Information security for use of cloud services A.5.20 Addressing information security within supplier agreements A.5.22 Monitoring, review and change management of supplier services A.8.30 Outsourced development

See all 37 Organisational Controls →

Frequently asked questions

Is ISO 27001 A.5.19 mandatory?

Annex A controls are not mandatory in the abstract. Clause 6.1.3 requires you to compare your risk treatment plan against Annex A and justify, in the Statement of Applicability, any control you exclude. If your risk assessment surfaces a risk that A.5.19 addresses, excluding it needs a documented, risk-based rationale that an auditor will test.

How do auditors test ISO 27001 A.5.19?

In two passes. First design: does a documented control exist, is it owned, and does it address the risk? Then operating effectiveness: the auditor samples records from across the audit period to confirm the control actually ran. A Stage 2 audit will typically pull several samples, so evidence that only exists for the month before the audit is a common finding.

How often should A.5.19 be reviewed?

ISO 27001 sets no fixed interval — it requires review at "planned intervals" and after significant change. Annual review is the norm most certification bodies expect, with an out-of-cycle review triggered by incidents, major system changes, restructures, or new regulatory obligations. Record the review date and outcome either way; an undated control is treated as unreviewed.

What does ISO 27001 A.5.19 map to in SOC 2 and NIST CSF?

A.5.19 aligns with SOC 2 CC9.2 and NIST CSF GV.SC-01, GV.SC-04, GV.SC-06. Evidence gathered for one framework will usually satisfy the others, which is the basis for a test-once, satisfy-many control library.

What was A.5.19 in ISO 27001:2013?

A.5.19 consolidates 1 control(s) from the 2013 edition: A.15.1.1. When transitioning, re-point the existing evidence rather than rebuilding it — the underlying requirement has not changed materially.